An apparatus includes a remote terminal unit (RTU) having one or more input/output (I/O) modules and a controller module. Each of the one or more I/O modules includes multiple I/O channels. The controller module includes at least one processing device configured to communicate with at least one industrial field device via the I/O channels of the I/O modules. The controller module includes a first connector, and a first of the one or more I/O modules includes a second connector. The first connector is configured to be physically connected to the second connector, and the first and second connectors are configured to transport data and power directly between the controller module and the first I/O module.